Supporting roller assembly for heat exchangers



Feb. 22, 1966 BRANDT 3,236,291

SUPPORTING ROLLER ASSEMBLY FOR HEAT EXCHANGERS Filed July 16, 1963 4 Sheets-Sheet 1 Feb. 22, 1966 H. BRANDT 3,236,291

SUPPORTING ROLLER ASSEMBLY FOR HEAT EXCHANGERS Filed July 16, 1963 4 Sheets-Sheet 2 Feb. 22, 1966 H. BRANDT 3,236,291

SUPPORTING ROLLER ASSEMBLY FOR HEAT EXCHANGERS Filed July 16, 1963 w 4 Sheets-Sheet s 1y U 11 I "TUTTI j if 6 I 2:: I: :17: n :T I 29 I g I wfiz SUPPORTING ROLLER ASSEMBLY FOR HEAT EXOHANGERS Filed July 16, 1963 H. BRANDT Feb. 22, 1966 4 Sheets-Sheet 4 United States Patent 3,236,291 SUPPORTING ROLLER ASSEMBLY FOR HEAT EXCHANGERS Herbert Brandt, Rothemuhle uber Olpe, Westphalia Vahlberg, Germany Filed July 16, 1963, Ser. No. 295,355 12 Claims. (Cl. 165-4) This application is a continuation-in-part of application Serial No. 831,207 filed August 3, 1959 and now abandoned.

This invention relates to regenerative heat exchangers using gaseous media such as air heated by hot flue-gases, including stationary heating surfaces and rotatable duct connections for the gas to be heated which rotate, coaxially, in relation to a stationary cylindrical regenerator chamber over the end surfaces thereof and within fixed connecting ducts for the heating gas, the said regenerator chamber containing the said stationary heating surfaces.

For convenience, air heating will usually be referred to hereinafter.

The rotating air duct connections, hereinafter referred to as rotary connections, are arranged at the inlet and outlet ends of the regenerator chamber, in mirror image relationship to an axial plane, and constantly connect two symmetrical annular sector shaped cross sections in the planes of the end surfaces of the regenerator chamber, with central inlet and outlet openings of stationary air ducts to which they are connected by stufiing box-like packings.

For making a sliding joint of the rotating annular sector shaped cross-sections with the end surfaces of the regenerator, with regenerators of large dimensions, separate frames carrying sealing means are mounted on the ends of each of the rotary connections. These sealing frames are movably mounted on adjustable rollers by which the size of the joint gap between the end surfaces of the regenerator and the sealing frames can be adjusted.

In prior constructions these supporting rollers are mounted on the sealing frames. Such a mounting within the hot, dust-containing gases results in very high wear because adequate lubrication under these conditions is not possible and the bearings cannot be elfectively sealed against the penetration of flue-gas dust.

It is proposed therefore to mount these supporting rollers not on the sealing frame itself but to position them outside the hot gas duct Where they are removed from the harmful action of the hot dust-containing gases. This arrangement at the same time gives easier accessibility and easier possibility of adjustment of the rollers during operation so that the adjustment of the joint gap can at all times be exactly adapted to the reigning operating conditions. As the supporting rollers have their bearings arranged outside the hot gas duct, the rollers, more specifically the disc parts thereof, are arranged to have a segmental part thereof projecting inwardly through slots in the duct wall. These disc parts are, in general, of constant thickness all round so that the clearance in the slots is constant.

The rotating sealing surfaces cover the rollers and slots, protecting the rollers against the action of the gases and the high temperatures, and sealing the slots at the same time against both flue-gas and air. If these rollers are so adjusted that a certain clearance remains, the slight quantity of air which is under higher pressure than the flue-gas and therefore escapes, sweeps over the rollers and protects them against strong heating by the hot flue-gases. In regenerative air heaters for small boiler plants, in view of the small dimension of the regenerator, there is only a small non-axial distortion, through non-uniform heat expansion, of the end surfaces of the regenerator. In these small regenerators therefore the provision of axially slid- 3,236,291 Patented Feb. 22, 1966 able gas-tight joints between the rotary connections and end surface of the regenerator is dispensed with and the possibility of adjustments of the rotary connections in height is accepted in order in this way to be able to compensate only for that heat expansion of the cylindrical generator chamber which is noticeable in its length. To compensate for the slight irregularities in the heat expansion of the regenerator end surfaces in these small regenerators, the rotary connections are angularly movably connected with the shaft through bores with convex sides, and are pressed uniformly against the supporting rollers by springs with adjustable force so that at all points of the sealing periphery the least possible variation of the joint gap is ensured.

In the accompanying drawings,

FIG, 1 is an axial sectional elevation, and

FIG. 2 is a plan, partly in section, of a first embodiment of the invention;

FIGS. 3 and 4 are, to a larger scale, a side view and a section, respectively, of the mounting of the supporting rollers shown in FIG. 1.

FIG. 5 is a plan view of a detail included in FIGS. 3 and 4;

FIG. 6 is a vertical section of a second embodiment of the invention.

FIG. 7 is a vertical section of a third embodiment of the invention; and

FIGS. 8 and 9, to a larger scale, are a section and a .side view, respectively, of the mounting of the supporting rollers shown in FIG, 7.

FIG. 10 is a vertical section of a fourth embodiment of the invention; and

FIG. 11 is a plan view, partly in section, of one am rangement of the sealing frames shown in FIG. 10.

In all the views corresponding parts bear the same reference numbers.

FIG. 1 is a vertical section of a regenerator of relatively small size having a vertical axis. The hot gases are led to a stationary regenerator chamber 1 from above through an upper stationary hot gas entry duct 2 and they leave the chamber through a lower stationary hot gas outlet duct 3. The air which is to be heated enters at the bottom through a stationary pipe bend 4 which is fixedly mounted within the stationary hot gas outlet duct 3, flows through a lower rotary connection 5 and over stationary heating surfaces 6 in the chamber 1 into an upper rotary connection 7, and thence into a stationary air outlet pipe bend 8 within the stationary hot gas inlet duct 2.

The two rotary connections 5 and 7 are journalled coaxially in relation to the stationary cylindrical regenerator chamber 1, and at all times connect two opposite annular sectors in each of the planes of rotation 9 and 9' at the end surfaces of the regenerator with the central air inlet and outlet openings 10' and 10 respectively of the bends 4 and 8. The rotary connection 7 is supported directly on upper supporting rollers 17 and also carries the weight of the lower rotary connection 5 which is suspended by means of a shaft 11 centrally from the upper rotary connection 7. Both rotary connections 5 and 7 are provided with bearings 30 having convexly curved walls 50 so that they can change their angular relationship to the shaft 11 in aXial planes in such a way that the flanges 29 of sealing frames 16 on the rotary connections 5 and 7 can remain parallel to the flanges 28 of the end surfaces of the regenerator even under uneven heat expansion and deformation.

The expansion in length is compensated by both sealing frames 16 on the rotary connections being pressed with regulatable force against the supporting rollers 17 in a yielding mounting by means of a central spring 27. This spring 27 is mounted on the air entry side on the hub of the rotary connections, the necessary spring pressure .being adjusted by the aid of nuts 12 on the shaft 11.

The drive of the rotary connections 5 and 7 is eflected through driving teeth of rod form constituting a toothed rim or lantern wheel 14 on the periphery of the sealing frame 16 of the upper rotary connection 7 and a toothed wheel 15 arranged on one side of the stationary hot gas duct 2, the driving shaft 13 carrying the wheel 15 being journalled outside the casing.

FIG. 2 shows diagrammatically and by way of example a plan view of the sealing surface of an end wall of the regenerator. For the sake of clearness only the outer wall 1 of the stationary regenerator chamber with one ;end flange. 28 thereof, and the supporting rollers 17 adjustably mountedon this end flange, are shown. Of the rotary connections only the joint making surfaces of .the sealing frames thereof are shown; these consist of an outer annular joint making are or flange 29 which in combination with four radial joint making strips 39 and the inner joint making strip 40, form the double, annulars'ector connecting cross-section. With the division of the regenerator end-surface by the radial sealing strips 39 disposed asshown in FIG. 2, the section left free for the passage of hot gas bears a ratio to the cross section for the air connections of about 2:1. The outer joint making flange 29 has a track surface 41 for the supporting rollers 17 on which the rotatable parts are supported. In FIGS. v3 and 4 an example of the construction of the supporting rollers 17 and their mounting at the top of the regenerator casing 1 is shown in detail. The supporting roller 17, through a longitudinal slot 18 in the upper flange 28 of the cylindrical regenerator chamber 1, is in contact with the joint-making track surface 41 of the upper joint-making flange 29 which, in combination with a further annular flange 42, constitutes the sealing frame 16, and, with rods 42', also constitutes the lantern wheel 14. For simplicity in mounting, the bearings for the rollers.17 together with the elements for adjusting their height are mounted on a common base plate 19 attached to the flange 28. The principle of this adjustable mounting is comparable with the mounting of a tension roller for a belt drive. A roller spindle 20 is fixed in a cradle formed of two parallel bars 21. The bars 21 are rockable, lever fashion, on a fixed axis 22 formed by a pivot and a supporting member 52 therefor attached to the base plate 19 and the angle of the bars 21 to the horizontal is adjusted by the aid of a screw 23 also fixedly attached to the base plate 19 whereby the projection of the roller 17 through the slot 18 can be adjusted to the value required from time to time. The roller 17 runs freely on its spindle 20 by the aid of two ball-bearings 25 which are so spaced within the hub of the roller 17 and on the spindle 20 that only slight lateral clearance in the longitudinal slot 18 is necessary for free running of the roller. To limit the free air gap between the roller 17 and the slot 18 two sheet metal screening members 26 are provided by which the air gap can be adjusted to the smallest possible value in the longitudinal direction of the slot 18 by shifting of the two members 26 relatively to one another. If these members 26 are made of L-form, as shown in FIG. 5, this length adjustment may be made by the aid of their short limbs 53; their long limbs 54 will serve for adjusting the breadth of the slot.

FIG. 6 shows another embodiment of the air heater in which the rotary connection 7 is supported directly on the upper supporting rollers 17 and also takes the weight of the lower rotary connection 5 which is suspended by the shaft 11 centrally from the upper rotary connection 7. The heat expansions arising within the cylindrical generator chamber 1 are compensated by spring movement of the sealing frame 16 on the lower rotary connection 5. The necessary value of the springing is achieved by a plurality of springs 44 arranged on the outer joint-making flange 29 of the sealing frame, which are constructed as adjustable compression springs. The

drive of the rotating part in this embodiment also is effected through a lantern wheel 14 on the periphery of the sealing frame 16 of the upper rotary connection 7.

FIGS. 7, 8 and 9 show another arrangement of the bearings of the adjustable supporting rollers 17 outside the regenerator casing. Each roller 17 in this case runs inside the regenerator casing, being carried at one end of a spindle 31 which is journalled at its other end outside the casing in a flanged bearing 32. The holding flange of this bearing 32 is provided with elongated holes 34 for the passage of bolts 33 secured to a base plate 37 on the casing, while the spindle 31 passes through an opening 51 of slot form in the casing, the holes 34 and slot form opening 51 permitting adjustment of the bearing in the vertical direction.

The adjustment of the bearing and thus the regulation of the joint gap 24 between the sealing frame 16 and the adjacent end of the regenerator is effected by the aid of an adjusting screw'36 which displaces an adjusting wedge 35 which is movable horizontally along an angle section 'slide rail 35 and which engages a corresponding inclined counter surface 32' on the flanged bearing. The elements for the height adjustment of the bearing 32 are secured on the base plate 37 which is secured to the casing. A gasket 38 of heat insulating material is interposed between the base plate 37 and the flange of the bearing 32, and is of such size as in all positions to cover the slot 51 in the casing through which the spindle 31 passes.

FIG. 10 shows another construction of air heater of relatively larger dimensions in which the rotary connections 5 and 7 are firmly secured to the central shaft 11. In this construction the shaft 11 is supported on an axial bearing, not shown, outside the regenerator casing and supports the weight ofboth rotary connections 5 and 7. The joint-making flanges of the connections are in this case provided on separate sealing frames 16, similarly to the sealing frame on the lower rotary connection 5 in the example shown in FIG. 6, for both connections, these two sealing frames 16 being movable in relationship to the rotary connections and supported on the supporting rollers 17 which are adjustable longitudinally of the casing. 7

FIG. 11 shows by way of example and diagrammatically a particular construction of the sealing frames 16 in which the outer joint making flange 29 for the supporting rollers 17 on both sides of the sector shaped air connection cross sections extends in arcuate formation only over an angle of about 60. To obtain satisfactory support and spacing of such sealing frames with this angle, at least twelve supporting rollers are necessary which are equally distributed round the periphery, as shown, so that each arcuate flange 29 is always supported by at least two rollers.

What I claim and desire to secure by Letters Patent is:

1. A regenerator heat exchanger comprising a regenerator casing, a stationary regenerator chamber disposed within and supported on said casing having upper and lower planar end surfaces, a central shaft passing therethrough, a heating gas entry duct in communication with the upper portion of said chamber, a heating gas outlet duct in communication with said gas entry duct via the lower portion of said chamber, upper and lower rotary duct connecting members having sector-shaped end portions and means for disposing said connecting members with respect to said chamber such that two opposite annular sections are connected via said chamber and means for disposing said connecting members in a changeable angular relationship with said shaft, an air entry pipe communicating with said lower duct, an air outlet pipe communicating with said upper duct, at least'three rollers substantially equally spaced from one another around the end surface of said chamber outside thereof and which support said connecting members, the lower rotary duct connecting member being supported from and rotatable with the upper rotary duct connecting member by: said central shaft, sealing frames mounted on said members at the sector-shaped ends in gas tight relation, means for mounting said sealing frames on said members so that said frames are axially movable with respect to said chamber, means for biasing said frames toward said chamber, and means for effecting alteration of the spacing of the sealing gap between the chamber and the frames from outside the casing during operation of the heat exchanger.

2. A heat exchanger according to claim 1 which comprises driving means for said upper rotary duct connecting member mounted externally of said casing and wherein said biasing means includes at least one spring component.

3. A heat exchanger according to claim 1 in which the sealing frames are secured to the connecting members in a relatively movable manner with axially slidable gastight joints.

4. A heat exchanger according to claim 1, having an annular flange extending radially from each end of said chamber, an annular bearing flange secured to the sector shaped end portions of each said connecting members and lying closely adjacent said outwardly extending annular flanges at the ends of said chamber, a plurality of bearing means located entirely exteriorly of said chamber and said connecting members, said bearing means being individually adjustable in a direction generally axially of said chamber, said bearings supporting said shafts, and rollers mounted on said shafts, the peripheries of said rollers contacting said bearing flanges whereby each of said duct connecting members is supported at an adjustable distance from said end surfaces.

5. A heat exchanger according to claim 4, wherein said rollers are of uniform axial thickness and said outwardly extending annular flanges are provided with slots, said rollers being located so that a segmental portion of each roller disc extends through a slot.

6. A heat exchanger according to claim 5, wherein cradle consisting of two bars each carrying a bearing near the center of its length is disposed one on each side of each supporting roller to support the axle shaft of one of said rollers, said cradle being pivoted at one of its ends to the casing, and an adjusting spindle by which the other end of said cradle is vertically adjustable.

7. A heat exchanger according to claim 5, in which two sheet metal screening members are adjustably and lockably mounted adjacent each said slot for adjustment of the length of the slot to agree with the length of the supporting roller segment extending through said slot.

8. A heat exchanger according to claim 7, in which the screening members are L shape and the shorter legs lie at the ends of the slot to provide the adjustment of the length of the slot and the longer legs extend along the sides of the slot to provide adjustment of the width of the slot.

9. A heat exchanger according to claim 4, wherein the shaft is fixedly connected with each supporting roller, each said shaft being journalled in said bearing means in an overhung position, said shaft with its roller extending into the interior of the device to support said annular bearing flange a slot for the passage of the said shaft and a sealing base plate between the bearing and the device fixedly connected to said device, said sealing plate covering the slot in all adjusted positions of said roller, with the base plate carrying all parts of the roller bearing and adjustment means.

10. A heat exchanger according to claim 4, wherein said bearing means are mounted in a block arranged to slide axially of said casing, and wedge means whereby said block may be moved.

11. A heat exchanger according to claim 4 wherein the stationary air outlet and inlet pipes are mounted adjacent to and communicating respectively with said upper and lower rotary duct connecting members and wherein said shaft is a connecting shaft co-ax-ial of and supported solely 'by said two connecting members and securing said members against axial movement and relative rotation with respect to one another while enabling said members to rotate in a plane to which said shaft is not normal.

12. A heat exchanger according to claim 11 wherein the air inlet pipe has a tension adjustable spring encircling said shaft so as to act on the lower connecting member.

References Cited by the Examiner UNITED STATES PATENTS 1,939,153 12/1933 V-illasuso l65-5 2,951,686 9/1960 Sandmann et al 1655 

1. A REGENERATOR HEAT EXCHANGER COMPRISING A REGENERATOR CASING, A STATIONARY REGENERATOR CHAMBER DISPOSED WITHIN AND SUPPORTED ON SAID CASING HAVING UPPER AND LOWER PLANAR END SURFACES, A CENTRAL SHAFT PASSING THERETHROUGH, A HEATING GAS ENTRY DUCT IN COMMUNICATION WITH THE UPPER PORTION OF SAID CHAMBER, A HEATING GAS OUTLET DUCT IN COMMUNICATION WITH SAID GAS ENTRY DUCT VIA THE LOWER PORTION OF SAID CHAMBER, UPPER AND LOWER ROTARY DUCT CONNECTING MEMBERS HAVING SECTOR-SHAPED END PORTIONS AND MEANS FOR DISPOSING SAID CONNECTING MEMBERS WITH RESPECT TO SAID CHAMBER SUCH THAT TWO OPPOSITE ANNULAR SECTIONS ARE CONNECTED VIA SAID CHAMBER AND MEANS FOR DISPOSING SAID CONNECTING MEMBERS IN A CHANGEABLE ANGULAR RELATIONSHIP WITH SAID SHAFT, AN AIR ENTRY PIPE COMMUNCIATING WITH SAID LOWER DUCT, AN AIR OUTLET PIPE COMMUNICATING WITH SAID UPPER DUCT, AT LEAST THREE ROLLERS SUBSTANTIALLY EQUALLY SPACED FROM ONE ANOTHER AROUND THE END SURFACE OF SAID CHAMBER OUTSIDE THEREOF AND WHICH SUPPORT SAID CONNECTING MEMBERS, THE LOWER ROTARY DUCT CONNECTING MEMBER BEING SUPPORTED FROM AND ROTATABLE WITH THE UPPER ROTARY DUCT CONNECTING MEMBER BY SAID CENTRAL SHAFT, SEALING FRAMES MOUNTED ON SAID MEMBERS AT THE SECTOR-SHAPED ENDS IN GAS TIGHT RELATION, MEANS FOR MOUNTING SAID SEALING FRAMES ON SAID MEMBERS SO THAT SAID FRAMES ARE AXIALLY MOVABLE WITH RESPECT TO SAID CHAMBER, MEANS FOR BIASING SAID FRAMES TOWARD SAID CHAMBER, AND MEANS FOR EFFECTING ALTERATIONS OF THE SPACING OF THE SEALING GAP BETWEEN THE CHAMBER AND THE FRAMES FROM OUTSIDE THE CASING DURING OPERATION OF THE HEAT EXCHANGER. 